The disclosure relates to a drive with emergency closing function.
For drives with an emergency closing function, various approaches are known.
Document DE 101 52 414 A1 and document DE 197 23 624 A1 present hydraulic drives for valve bodies of valves with fixed mechanical coupling between an actuating cylinder and the valve body. The valve body is biased in the closing direction of the respective valve by a respective emergency spring by which the valve is closed in the event of a fault.
A disadvantage of such hydraulic drives is that the emergency spring is relaxed or stressed during every adjustment movement of the valve body by the drive.
Document DE 103 08 017 B4 presents a hydraulic drive having a mechanical coupling and having an emergency spring, wherein in a normal operating mode, the emergency spring in the stressed state is moved jointly with the coupling. In an emergency operating mode, a knee lever device which holds the emergency spring stressed is released such that the emergency spring relaxes and thus spreads or lengthens the mechanical coupling. The valve is thereby closed.
A disadvantage of the latter drives is the outlay in terms of apparatus for the mechanical release function, which must be moved jointly with the emergency spring.
By contrast, it is the object of the disclosure to provide a drive which is simple in terms of apparatus and which has an emergency closing function.
Said object is achieved by a drive with emergency closing function.